Wells used in the production of gas, may also produce quantities of water and gas condensate. Some of these gas wells are affected by halite scale, which deposits on wellbore tubulars and may also deposit within the reservoir rock near the wellbore. This halite scale has the potential to restrict gas flow and may cause a complete blockage of the well in extreme conditions.
It is generally believed that the predominant mechanism for this halite scale deposition is the de-hydration of highly saline formation waters by natural gas as the gas flows into the near wellbore region or the well itself. If the water that lies below or within the gas reservoir is highly saline, it may take only a small amount of de-hydration to take the water past salt saturation, resulting in halite being precipitated out of solution. De-hydration occurs because, as gas expands (as it does when it flows from a high pressure reservoir into a low pressure well), its capacity to hold water increases. One way that has been used in the past to prevent the salt dropping out is to introduce fresh (or low salinity) water to the well. This fresh water dilutes the brine so that any water evaporation maintains the brine in an under saturated state.
The majority of existing systems in the oil and gas industry for delivering fresh water to a well either are deployed above the production packer via a chemical injection valve or are retrofitted to an existing well completion design by inserting an additional capillary line to a given depth inside the well tubulars where water is then injected through a single opening.
However, there are scenarios where these existing systems do not perform well:                in deviated wells, the water injected may flow along the low side of the well only, thus keeping only a part of the well clear of halite;        where formation water production is not well defined, risking over injection of water, leading to the accumulation of liquid water in the wellbore, resulting in increased hydrostatic head and the loss of well production;        where gas inflow locations are not well defined and the injection point (or points) do not cover the inflow zones;        where only small amounts of formation water are produced and is immediately evaporated on entry into the wellbore, thus precipitating halite before the gas encounters the injected water;        where only small amounts of formation water are produced and are evaporated prior to entry into the wellbore, thus precipitating halite in the near wellbore region of the well;        in a combination of the above scenarios.        
Furthermore, water in a liquid form may have a significant residence time in the well (in the form of travel time up the wellbore) before being evaporated by the natural gas. This can lead to significant deposition at the bottom of the well.